Undescended Testicle

The testicles form in the abdomen and descend down into the scrotum through the inguinal canal during the 3rd trimester of pregnancy. Any testis that is not located in the scrotum is considered to be undescended.

This condition is fairly common, with about 1% of full term boys having an undescended testis at one year of age. In many cases an undescended testicle is detected at birth, but the testicle will descend spontaneously within the first 3 to 6 months of life.

Testicles require the cooler environment of the scrotum in order to develop properly. Evidence suggests that damage to the germ cells of the testicle, which give rise to sperm later in life, can occur as early as 12 to 18 months if the testicle remains undescended. Boys with undescended testicles also have an increased risk of developing testicular cancer, and early identification of testicular cancer is only possible if the testicle is located in the scrotum. Due to these concerns, treatment of undescended testicles is recommended within the first year of life.

Surgical treatment of undescended testicles, called an orchiopexy, is an outpatient procedure usually accomplished through a small groin incision. The complication rate of the procedure is minimal and children recover quickly from the procedure.

In some circumstances, the undescended testicle is located within the abdomen and a laparoscopic approach to the orchiopexy is necessary. Most intra-abdominal testis can be brought down with a single stage procedure, however, in some cases the testicle is positioned so high within the abdomen that division of the main testicular artery is necessary in order to achieve enough length to bring the testicle into the scrotum (Fowler-Stephens orchiopexy). In this situation, blood flow to the testicle occurs through its secondary arterial supply, the artery to the vas deferens. The Fowler-Stephens orchiopexy is usually performed as a 2 stage procedure to minimize the risks of testicular atrophy associated with division of the main testicular artery. In some cases, the testicle is completely absent (vanishing testis) or the testicle is found to be a non-functioning small remnant (testicular nubbin) which needs to be removed (orchiectomy).

If treated early, there is a good chance that the affected testicle will develop normally, however, if the testicle is abnormal to begin with its growth may be affected. Overall fertility rates are usually not affected unless both testicles are undescended. The undescended testicle needs to be monitored long term, even after the testicle is brought into the scrotum, due to the risk of testicular cancer developing later in life.